Batten down the hatches or just get an umbrella? | Environment

Apparently, it’s finally going to rain in Sacramento and the media is slightly panicking.. For the past three days I’ve been reading about flood warnings and something called an atmospheric river.  While I’m the first to evacuate when the authorities tell me to, I’m also skeptical of these warnings.  They are pretty widespread.  Do I need to do anything or is the rain going to hit up in the hills or north of here?